Stream-lined hydrometer bulb



Nov. 12, 1935. G. RUEHFEL 2,020,968

STREAM LINED HYDROMETER BULB Filed Aug. 18, 1954 T1 El- Patented Nov. 12, 1935 UNITED STATES PATENT OFFICE 2 Claims.

eter and its leading object is to provide an hydrometer having a stream-lined bulb constructed in such manner that a rounded entrance terminal is provided, and the weighting alloy or metal will interlock internally with this rounded bulb end, when the metal is melted.

A further object of the invention is to provide an hydrometer bulb of this general construction,

which will have an approximately smooth, seamless, exterior, so that it can be thoroughly cleaned by a wiping action.

With the above and other objects in view the invention consists in certain new and useful constructions, combinations and arrangements of parts, clearly described in the following specification, and fully illustrated in the accompanying drawing, in which:-

Fig. l is a side elevation of the improved bulb,

broken away, for convenience.

Fig. 2 is a similar view, partly in longitudinal section, showing the insertable section of the lower end of the bulb, being formed to seal the lower end of. the bulb.

Fig. 3 is a similar view, showing the inserted element or section fused in place and rounded to seal the bulb.

Fig. 4 is a transverse sectional view taken on line 4-4 of Fig. 1 looking in the direction of the arrows.

Referring to the accompanying drawing illustrating the practical construction of the invention and. the method of carrying out the invention, 5 designates a glass tube, which is drawn from cylindrical stock to provide the tapered lower end t, and the reduced upper end I, in which the usual scale 8 is inserted, after which the upper end of the reduced tube section 7 is sealed over, or closed.

In the tapered lower end of the bulb tube 5 a fusible metal is placed, to weight the tube, so that it will readily descend into the liquid to be tested. If this fusible metal is not properly anchored or interlocked to the wall of the tube, it will shift,

5 or separate from the lower end of the tube, and by this shifting cause the tube to break. If the point of engagement between the fusible metal and the bulb tube is weak, the lower end of the bulb will break, thus ruining the hydrometer.

Hydrometers are inserted in acids, oils and other liquids, and it is good practice to wipe them clean, so it is desirable and. in fact essential that the surfaces of the bulbs be substantially seamless.

In forming my improved hydrometer bulb the cylindrical tube is reduced to a taper, and the restricted lower end of this tapered portion is (01. 265-45) This invention relates to an improved hydromleft with a central or unclosed opening. In this opening a smaller tube section 9, having a sharper tapered portion 18, and a portion ll of indefinite length is partly inserted in the tapered end of the bulb tube 5, and the overlapping portions of the 5 two tubes are then subjected to fusion in the presence of a Bunsen flame, so that the external surface of the hydrometer bulb will be seamless.

At the same time this operation reduces the internal diameter of the tube section 5. The tube 10 9 is then subjected to a spinning operation, in the presence of. a Bunsen flame, so that the wall of the tube 9 is progressively restricted until it is wholly closed upon itself, and this operation is then finished by trimming the tube 9 so that a 15 semi-spherical terminal is provided for the hydrometer bulb.

By this operation an internal shoulder I2 is provided for the receptacle [3, which is of greater relative diameter than the throat M of the recep- 20 tacle.

Fusible metal in the form of small pellets is then dropped through the reduced tube 1 into the receptacle I3, and melted in the presence of a Bunsen flame. A weight I5 is thus provided which is 25 anchored to the receptacle l3, by reason of the shoulder I2, which will not shift within the bulb, or break through the bulb. The point of interlocking connection between the fusible metal weight and the bulb includes a. wall having double 30 thickness, which also relieves the bulb from excessive strain, and strengthens the lower end of the hydrometer so that it will stand shocks better and give better service.

Having described my invention I claim as 35 new:-

1. An hydrometer bulb consisting of a main section and a secondary section inserted in the lower end thereof and fused to the wall of the main section to provide a conical internal flange spaced 40 from the wall of the main section and ballast metal fused in the main and secondary sections against both sides of the conical flange and interlocked against longitudinal displacement thereby.

2. An hydrometer bulb consisting of a main 45 section having a reduced lower end provided with an internal conical flange fused thereto and located above the bottom end of the bulb to provide a chamber below the upper end of the conical flange, said conical flange projecting upwardly in t0 the bulb and being spaced at its upper ends from the wall of the bulb, and ballast metal fused in said chamber and above and upwardly of the conical flange and interlocked thereby against longitudinal displacement.

GEORGE RUEI-IFEL. 

